LAUSR

A novel method of reverse migration micellar electrokinetic chromatography (RM‐MEKC) using 2,2′‐azinobis‐(3‐ethylbenzthiazoline‐6‐sulphonate) as oxidation‐free radical was developed to screen the major antioxidants from Sanyetangzhiqing (SYTZQ), which is a new patent drug for diabetes. For simultaneous detection and separation of 2,2′‐bis (3‐ethylbenzothiazoline‐6‐sulfonic acid) ammonium salt (ABTS+) and chemical components of SYTZQ, the key factors were optimized and the method was validated under the optimal conditions. All the relative standard deviations of recovery, precision, and stability were below 6.6%. Based on these, the RM‐MEKC method has been successfully used to screen the main antioxidants from SYTZQ tablets. Five compounds, including rosmarinic acid, salvianolic acid B, lithospermic acid, hyperoside, and isoquercetin, were separated and identified as the major antioxidants. There was a linear relationship with correlation coefficient of 0.923 between the total amount of major antioxidants and total antioxidative activity of SYTZQ. Consequently, these five ingredients could be selected as combinatorial markers for quality control of SYTZQ, and the established method was concluded to be a simple, reliable, and powerful tool to screen and quantify active compounds for quality evaluation of SYTZQ.